Oral implantology is a surgical technique which has come into rather wide use in recent years By this technique one or more implant devices are surgically and permanently affixed within or around the bone structure of a patient's jaw to serve as a support for the bridgework of artificial teeth. The implant device may be designed to have a portion set directly into the jawbone, i.e., an endosseous implant, or to be secured to the surface of the jawbone below the gum line, i.e., a subperiosteal implant. In either case, the implant device includes one or more projecting supports or posts which extend through the gum tissue to receive a prosthesis.
At the present time, there are various types of endosseous implants used in dentistry and oral surgery. The two most common types of endosseous implant devices are the cylindrical implant and the blade implant.
In the cylindrical implant, first a hole is drilled into the patient's jawbone, and then the cylindrical portion of the implant is inserted into the hole. The cylindrical implant is retained in the hole formed in the jawbone by pins, threads, etc. The cylindrical implant has a neck portion and an integral head portion which protrudes above the gum line for supporting and coupling an artificial tooth thereto.
The blade implant is implanted in a similar manner. First a groove is cut into the patient's jawbone, and then the implant is inserted into the groove in the patient's jawbone and secured in a conventional manner. The blade type also has an integral head which protrudes up above the gum line for attaching an artificial tooth thereto.
Over the years several studies have indicated that it is preferred that dental implants comprise detachable sections including an engaging section and a neck section so that initially, the engaging section of the implants can be completely retained within the jawbone and below the gum, until after the gum has healed and at least some bone material has grown about the engaging section. Accordingly, more recent dental implants are typically constructed of several pieces, i.e., including a detachable implant head.
A typical procedure for implanting a cylindrical dental implant device with a detachable implant head is disclosed in U.S. Pat. No. 4,439,152 to Small, which is incorporated by reference. In summary, first a hole is drilled into the patient's jawbone for receiving the cylindrical implant. Next, the implant device is inserted into the hole in the patient's jawbone, completely within the jawbone. The threaded hole at the top of the implant is closed with a removable plug. The gum is stitched closed and allowed to heal for two to three months. Subsequently, the patient's gum is reopened, the plug is removed and an implant head member is mounted on the implant. The implant head has a threaded shaft portion which screws into the bore of the implant cylinder for securing it thereto. Finally, a prosthesis or an artificial tooth is attached to the implant head.
Other examples of cylindrical implants with a threaded implant head are disclosed in U.S. Pat. Nos. 4,439,152 to Small and 4,793,808 to Kirsch. However, these cylindrical implants have numerous disadvantages. For example, these cylindrical implants have a tendency to become loose when rotational and/or lateral stresses or movements generated by chewing or grinding of the patient's teeth are applied thereto.
The blade implant was developed to resist rotational and lateral movements or stresses caused by the patient chewing or grinding his or her teeth. However, the blade implant also suffers from numerous disadvantages such as breaking. Another common problem with blade implants has been fibro-osseous integration, postulated by Charles Weiss Fibro-osseous integration occurs when a greater amount of fibrous tissue, i.e., a type of connective tissue, opposes the blade implant than the amount of bone tissue opposing the blade implant. Thus, there have been several attempts to combine a cylindrical implant and a blade implant Examples of such implant devices are disclosed in U.S. Pat. Nos. 2,449,522 to White; 4,622,010 to Koch; and 4,762,492 to Nagai. However, these implant devices require a large portion of the patent's jawbone to be removed for receiving the lower portion of the implant therein. Moreover, the implant devices are also difficult to implant in small areas between teeth.
Examples of implant devices which utilize pins for stabilizing the implant are disclosed in U.S. Pat. Nos. 2,857,670 to Kiernan, Jr. and 3,579,831 to Stevens et. al.
This invention addresses these problems in the art, along with other needs which will become apparent to those skilled in the art once given this disclosure.